Method and apparatus for ATM address resolution

Abstract

In a generic, end-to-end address resolution methodology, destination addresses in one format are translated into local addresses of different formats for purposes of routing calls across a plurality of interconnected networks which use different address formats. Translation of addresses is accomplished through either database query or by conversion algorithm. To facilitate routing across a particular network, the signaling message of the call is repacked with the local address as the routing address. The original destination address is preserved and carried transparently across that network. The signaling message is then repacked with the destination address as the routing address. Bi-level addressing schemes are supported, so that a network-level destination address and user-level destination address may both be carried transparently across a particular network.

We claim:  
     
       1. A method for routing a call across a first ATM network toward a second ATM network, each network having an addressing format, the addressing format of the first network being different from the addressing format of the second network, the call having an associated signaling message specifying a destination address in the second network, the method comprising the steps of: 
       translating the destination address into a local address in the addressing format of the first network, wherein said step of translating further includes querying an address translation database populated with an address interface identifier pair to obtain the local address, wherein the interface identifier pair specifies as the local address the address of an egress port in the first network and specifies the destination address, and wherein the local address corresponds to the destination address such that routing the call to the local address causes the call to be routed toward the second network;  
       repacking the signaling message with the local address as a routing address;  
       routing the call through the first network using the local address; and  
       repacking the signaling message with the destination address as the routing address.  
     
     
       2. The method of claim  1  further comprising the step of forwarding the call toward the second network. 
     
     
       3. The method of claim  1  wherein the step of routing the call through the first network includes the substep of 
       carrying the destination address transparently across the first network.  
     
     
       4. The method of claim  3 , wherein the signaling message further specifies a destination address in an end system beyond the second network, and wherein the step of routing the call through the first network further includes the substep of 
       carrying the end system destination address transparently across the first network.  
     
     
       5. The method of claim  3 , wherein the signaling message further specifies a destination address in an end system beyond the second network, wherein the destination address is a network-level address and the end system destination address is a user-level address, and wherein the step of routing the call through the first network further includes the substep of 
       carrying the end system destination address transparently across the first network.  
     
     
       6. The method of claim  1  wherein the step of repacking the signaling message with the local address includes the substeps of 
       demoting the destination address from a first signaling message parameter to a second signaling message parameter; and  
       inserting the local address into the first signaling message parameter.  
     
     
       7. The method of claim  6  wherein the step of repacking the signaling message with the destination address includes the substeps of 
       discarding the local address from the first signaling message parameter; and  
       promoting the destination address to the first signaling message parameter.  
     
     
       8. An apparatus for use in routing a call across a first ATM network toward a second ATM network, each network having an addressing format, the addressing format of the first network being different from the addressing format of the second network, the call having an associated signaling message specifying a destination address in the second network, the apparatus comprising: 
       an address resolution server for translating the destination address into a local address in the addressing format of the first network, wherein the address resolution server includes means for querying an address translation database populated with an address interface identifier pair to obtain the local address, wherein the interface identifier pair specifies as the local address the address of an egress port in the first network, and wherein at least one interface identifier pair further specifies the destination address, the local address corresponding to the destination address such that routing the call to the local address causes the call to be routed toward the second network;  
       means for repacking the signaling message with the local address as a routing address;  
       means for routing the call through the first network using the local address; and  
       means for repacking the signaling message with the destination address as the routing address.  
     
     
       9. The apparatus of claim  8  further comprising means for forwarding the call toward the second network. 
     
     
       10. The apparatus of claim  8  wherein the means for routing the call through the first network includes 
       means for carrying the destination address transparently across the first network.  
     
     
       11. The apparatus of claim  10 , wherein the signaling message further specifies a destination address in an end system beyond the second network, and wherein the means for routing the call through the first network further includes 
       means for carrying the end system destination address transparently across the first network.  
     
     
       12. The apparatus of claim  10 , wherein the signaling message further specifies a destination address in an end system beyond the second network, wherein the destination address is a network-level address and the end system destination address is a user-level address, and wherein the means for routing the call through the first network further includes 
       means for carrying the end system destination address transparently across the first network.  
     
     
       13. The apparatus of claim  8  wherein the means for repacking the signaling message with the local address includes 
       means for demoting the destination address from a first signaling message parameter to a second signaling message parameter; and  
       means for inserting the local address into the first signaling message parameter.  
     
     
       14. The apparatus of claim  13 , wherein the means for repacking the signaling message with the destination address includes 
       means for discarding the local address from the first signaling message parameter; and  
       means for promoting the destination address to the first signaling message parameter.  
     
     
       15. A method for routing a call across a first ATM network toward a second ATM network, each network having an addressing format, the addressing format of the first network being different from the addressing format of the second network, the call having an associated signaling message specifying a destination address in the second network, the method comprising the steps of: 
       translating the destination address into a local address in the addressing format of the first network, wherein said step of translating further includes applying a conversion algorithm to the destination address to obtain the local address, wherein the local address corresponds to the destination address such that routing the call to the local address causes the call to be routed toward the second network;  
       repacking the signaling message with the local address as a routing address;  
       routing the call through the first network using the local address; and  
       repacking the signaling message with the destination address as the routing address.  
     
     
       16. The method of claim  15  further comprising the step of forwarding the call toward the second network. 
     
     
       17. The method of claim  15  wherein the step of routing the call through the first network includes the substep of 
       carrying the destination address transparently across the first network.  
     
     
       18. The method of claim  17 , wherein the signaling message further specifies a destination address in an end system beyond the second network, and wherein the step of routing the call through the first network further includes the substep of 
       carrying the end system destination address transparently across the first network.  
     
     
       19. The method of claim  17 , wherein the signaling message further specifies a destination address in an end system beyond the second network, wherein the destination address is a network-level address and the end system destination address is a user-level address, and wherein the step of routing the call through the first network further includes the substep of 
       carrying the end system destination address transparently across the first network.  
     
     
       20. The method of claim  15  wherein the step of repacking the signaling message with the local address includes the substeps of 
       demoting the destination address from a first signaling message parameter to a second signaling message parameter; and  
       inserting the local address into the first signaling message parameter.  
     
     
       21. The method of claim  20  wherein the step of repacking the signaling message with the destination address includes the substeps of 
       discarding the local address from the first signaling message parameter; and  
       promoting the destination address to the first signaling message parameter.  
     
     
       22. A method for routing a call across a first ATM network toward a second ATM network, each network having an addressing format, the addressing format of the first network being different from the addressing format of the second network, the call having an associated signaling message specifying a destination address in the second network, wherein the signaling message further specifies a destination address in an end system beyond the second network, wherein the destination address is a network-level address and the end system destination address is a user-level address, the method comprising the steps of: 
       translating the destination address into a local address in the addressing format of the first network;  
       repacking the signaling message with the local address as a routing address;  
       routing the call through the first network using the local address, wherein the step of routing the call through the first network further includes carrying the end system destination address transparently across the first network; and  
       repacking the signaling message with the destination address as the routing address.  
     
     
       23. The method of claim  22  further comprising the step of forwarding the call toward the second network. 
     
     
       24. The method of claim  22  wherein the step of translating the destination address into a local address includes the substep of 
       querying an address translation database populated with an address interface identifier pair to obtain the local address.  
     
     
       25. The method of claim  22  wherein the step of translating the destination address into a local address includes the substep of 
       querying an address translation database populated with an address interface identifier pair to obtain the local address, wherein the interface identifier pair specifies as the local address the address of an egress port in the first network.  
     
     
       26. The method of claim  22  wherein the step of translating the destination address into a local address includes the substep of 
       querying an address translation database populated with an address interface identifier pair to obtain the local address, wherein the interface identifier pair specifies as the local address the address of an egress port in the first network and specifies the destination address, and wherein the local address corresponds to the destination address such that routing the call to the local address causes the call to be routed toward the second network.  
     
     
       27. The method of claim  22  wherein the step of translating the destination address into a local address includes the substep of 
       applying a conversion algorithm to the destination address to obtain the local address.  
     
     
       28. The method of claim  22  wherein the step of translating the destination address into a local address includes the substep of 
       applying a conversion algorithm to the destination address to obtain the local address, wherein the local address corresponds to the destination address such that routing the call to the local address causes the call to be routed toward the second network.  
     
     
       29. The method of claim  22  wherein the step of repacking the signaling message with the local address includes the substeps of 
       demoting the destination address from a first signaling message parameter to a second signaling message parameter; and  
       inserting the local address into the first signaling message parameter.  
     
     
       30. The method of claim  29  wherein the step of repacking the signaling message with the destination address includes the substeps of 
       discarding the local address from the first signaling message parameter; and  
       promoting the destination address to the first signaling message parameter.  
     
     
       31. An apparatus for use in routing a call across a first ATM network toward a second ATM network, each network having an addressing format, the addressing format of the first network being different from the addressing format of the second network, the call having an associated signaling message specifying a destination address in the second network, the apparatus comprising: 
       an address resolution server for translating the destination address into a local address in the addressing format of the first network, wherein the address resolution server includes means for applying a conversion algorithm to the destination address to obtain the local address, wherein the local address corresponds to the destination address such that routing the call to the local address causes the call to be routed toward the second network;  
       means for repacking the signaling message with the local address as a routing address;  
       means for routing the call through the first network using the local address; and  
       means for repacking the signaling message with the destination address as the routing address.  
     
     
       32. The apparatus of claim  31  further comprising 
       means for forwarding the call toward the second network.  
     
     
       33. The apparatus of claim  31  wherein the means for routing the call through the first network includes 
       means for carrying the destination address transparently across the first network.  
     
     
       34. The apparatus of claim  33 , wherein the signaling message further specifies a destination address in an end system beyond the second network, and wherein the means for routing the call through the first network further includes 
       means for carrying the end system destination address transparently across the first network.  
     
     
       35. The apparatus of claim  33 , wherein the signaling message further specifies a destination address in an end system beyond the second network, wherein the destination address is a network-level address and the end system destination address is a user-level address, and wherein the means for routing the call through the first network further includes 
       means for carrying the end system destination address transparently across the first network.  
     
     
       36. The apparatus of claim  31  wherein the means for repacking the signaling message with the local address includes 
       means for demoting the destination address from a first signaling message parameter to a second signaling message parameter; and  
       means for inserting the local address into the first signaling message parameter.  
     
     
       37. The apparatus of claim  36 , wherein the means for repacking the signaling message with the destination address includes 
       means for discarding the local address from the first signaling message parameter; and  
       means for promoting the destination address to the first signaling message parameter.  
     
     
       38. An apparatus for use in routing a call across a first ATM network toward a second ATM network, each network having an addressing format, the addressing format of the first network being different from the addressing format of the second network, the call having an associated signaling message specifying a destination address in the second network, wherein the signaling message further specifies a destination address in an end system beyond the second network, wherein the destination address is a network-level address and the end system destination address is a user-level address, the apparatus comprising: 
       an address resolution server for translating the destination address into a local address in the addressing format of the first network;  
       means for repacking the signaling message with the local address as a routing address;  
       means for routing the call through the first network using the local address, wherein the means for routing further includes means for carrying the end system destination address transparently across the first network; and  
       means for repacking the signaling message with the destination address as the routing address.  
     
     
       39. The apparatus of claim  38  further comprising 
       means for forwarding the call toward the second network.  
     
     
       40. The apparatus of claim  38  wherein the address resolution server includes 
       means for querying an address translation database populated with an address interface identifier pair to obtain the local address.  
     
     
       41. The apparatus of claim  38  wherein the address resolution server includes means for querying an address translation database populated with an address interface identifier pair to obtain the local address, wherein the interface identifier pair specifies as the local address the address of an egress port in the first network. 
     
     
       42. The apparatus of claim  38  wherein the address resolution server includes 
       means for querying an address translation database populated with an address interface identifier pair to obtain the local address, wherein the interface identifier pair specifies as the local address the address of an egress port in the first network, and wherein at least one interface identifier pair further specifies the destination address, the local address corresponding to the destination address such that routing the call to the local address causes the call to be routed toward the second network.  
     
     
       43. The apparatus of claim  38  wherein the address resolution server includes means for applying a conversion algorithm to the destination address to obtain the local address. 
     
     
       44. The apparatus of claim  38  wherein the address resolution server includes means for applying a conversion algorithm to the destination address to obtain the local address, wherein the local address corresponds to the destination address such that routing the call to the local address causes the call to be routed toward the second network. 
     
     
       45. The apparatus of claim  38  wherein the means for repacking the signaling message with the local address includes 
       means for demoting the destination address from a first signaling message parameter to a second signaling message parameter; and  
       means for inserting the local address into the first signaling message parameter.  
     
     
       46. The apparatus of claim  45 , wherein the means for repacking the signaling message with the destination address includes 
       means for discarding the local address from the first signaling message parameter; and  
       means for promoting the destination address to the first signaling message parameter.